The present invention relates to a method for indicating that an LED flash light for an aircraft such as an anti-collision or beacon or strobe LED light has reached a near-end-of-life status. Furthermore, the present invention relates to an LED flash light for an aircraft, such as an anti-collision or beacon or strobe aircraft light.
Aircrafts are provided with different types of flash lights such as anti-collision, beacon or strobe lights.
Beacon lights are known as anti-collision lights in the aircraft industry. Beacon and anti-collision lights are synonymous terms. In order to attract the required optical attention on the side of pilots, the intensity of light emitted by an anti-collision aircraft light must follow the formula of Blondel-Rey.
For maintenance and service reasons, anti-collision lights for aircrafts and, in general, aviation flash lights ever more often include LEDs instead of xenon light sources. However, the properties of LEDs degrade due to aging effects. It is known that LEDs degrade depending on the temperature and their useful life so far. These two influencing factors result in a reduced light intensity over time. This can be compensated by increasing the operational current supplied to the LEDs.
With LED technology and other light sources that rather degrade than completely fail at one point in time, such as filament based lights, it is very 5 difficult to determine when these lights no longer meet the photometric requirements. For these light sources it might be suitable to internally monitor and control the light sources accordingly. The control unit recognizes that an end-of-light status is reached but communicating this state so that the appropriate action can be performed (namely replacement) is difficult for these 10 lights. Typically, these flashing lights have no signal line or other electronic communication means to indicate an end-of-life status to a remote maintenance device or observer. The flashes are of fairly high intensity so that a direct observation of the light may be harmful to the observer, and some of the lights are located on top of the aircraft, thus not allowing to see a flashing blue LED or similar device from a distance in daylight.
Accordingly, there is a need in the state of the art to indicate in a fairly easy manner that an LED flash light has reached its end-of-light status.